81122113 has 4 divisors (see below), whose sum is σ = 85894020. Its totient is φ = 76350208.

The previous prime is 81122033. The next prime is 81122159. The reversal of 81122113 is 31122118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31122118 = 2 ⋅15561059.

It can be written as a sum of positive squares in 2 ways, for example, as 74857104 + 6265009 = 8652^2 + 2503^2 .

It is a cyclic number.

It is not a de Polignac number, because 81122113 - 2¹⁷ = 80991041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81122213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2385928 + ... + 2385961.

It is an arithmetic number, because the mean of its divisors is an integer number (21473505).

Almost surely, 2^81122113 is an apocalyptic number.

It is an amenable number.

81122113 is a deficient number, since it is larger than the sum of its proper divisors (4771907).

81122113 is a wasteful number, since it uses less digits than its factorization.

81122113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4771906.

The product of its digits is 96, while the sum is 19.

The square root of 81122113 is about 9006.7815006250. The cubic root of 81122113 is about 432.8921908365.

The spelling of 81122113 in words is "eighty-one million, one hundred twenty-two thousand, one hundred thirteen".